Petroleum crude oil conversion process



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A TTORNEYS United States Patent O 3,544,450 PETROLEUM CRUDE OILCONVERSION PROCESS Laurence O. Stine, Western Springs, Ill., assiguor toUniversal Oil Products Company, Des Plaines, Ill., a corportion ofDelaware Filed Sept. 9, 1968, Ser. No. 758,217 Int. Cl. Cg 23/02, 23/00U.S. Cl. 208-93 7 Claims ABSTRACT OF THE DISCLOSURE A petroleum crudeoil feedstock is converted into more Valuable products by a combinationprocess including the steps of contacting, separation, catalyticconversion and further separation and recovery.

BACKGROUND OF THE INVENTION This invention relates to a method for theconversion of a petroleum crude oil feedstock into more valuableproducts. Further, this invention specifically relates to a method forcontacting a petroleum crude oil feedstock with a CS-C containingnaphtha stream in a contacting zone maintained under contactingconditions wherein a heavy fraction stream having an initial boilingpoint above about 650 F. is separated from a light fraction streamhaving an end boiling point of from above about 650 F. to 850 F. Thislight fraction stream is subsequently catalytically converted into morevaluable products while the heavy fraction stream bypasses the catalyticreaction portion of the process and is subsequently separated in afractionation zone.

As used herein the term petroleum crude oil feedstoc is meant to includeheavy oils extracted from tar sands, topped or reduced crudes, vacuumresiduum (Vacuum tower bottoms products) and especially those petroleumcrude oils referred to as black oils which contain a signicant quantityof asphaltic materials and high concentrations of sulfur, as well aslarge quantities of nitrogenous compounds and high molecular weightorgano-metallic complexes principally comprising nickel and vanadium.These black oils include those hydrocarbon charge stocks of which atleast about 10% by volume boils above a temperature of about 1050 F.These black oils usually have an API gravity, at 60 F., of less than20.0 and further, sulfur concentrations are usually more than 1% byweight and often in excess of 3% by weight.

)In brief, the invention provides a method for converting such petroleumcrude oils, and especially black oils, to more valuable productsinasmuch as my process sharply reduces the sulfur and asphaltic contentof the charge passing to the reaction Zone so that a significantproportion of the charge can be converted into distillable hydrocarbons,that is, those boiling below about 1050 F.

Therefore, `it is a further object of this invention to provide aprocess for the conversion of a petroleum crude oil feedstock wherein aheavy fraction stream comprising major amounts of asphaltenes,organo-metallic complexes, carbon residue precursors, and dirt isseparated in a contacting zone from a light fraction stream so that theheavy phase is used to bypass the reactor section of my process. Thisheavy fraction stream is subsequently combined in the fractionationsection of my process with that nondistillable material, if any,remaining from the catalytic conversion of the light fraction stream.

Therefore, in accordance with one embodiment of my invention, there isprovided a method for the conversion of a petroleum crude oil feedstockincluding the steps of contacting this feedstock with a C6-C8 containingnaphtha stream in a contacting zone maintained under contactingconditions, wherein a heavy fraction stream is separated "ice from alight fraction stream with the heavy fraction stream, being then passedinto a fractionation zone maintained under distillation conditions, andthe light fraction stream in admixture with a hydrogen containing gasstream being passed to a catalytic reaction zone maintained underconversion conditions, wherein the light fraction stream is at leastpartially converted into more valuable products and, from the effluentof the catalytic reaction zone, normally gaseous components, andnormally gaseous and normally liquid conversion products, including aCif-C8 containing naphtha stream are separated and recovered.

DESCRIPTION OF THE DRAWING This invention can be most clearly describedand illustrated with reference to the attached drawing. While ofnecessity, certain limitations must be present in such schematicdescriptions, no intention is meant thereby to limit the generally broadscope of this invention.

As stated hereinabove, the rst step of the method of the presentinvention comprises contacting a petroleum crude oil feedstock with aCG-Cs containing naphtha stream in a contacting zone maintained undercontacting conditions wherein a heavy fraction stream is separated froma light fraction stream. In the drawing, this first step is representedas taking place in contacting zone 4. The contacting zone must befurnished with the petroleum crude oil feedstock and the Cs-CBcontaining naptha stream. In the drawing, which illustrates a preferredembodiment of my invention, there is provided line 1 for passage of areaction gas such as hydrogen to admix with a Cs-Cs containing napthastream in line 2 for admixture with the petroleum crude oil feedstockpassing via line 3 into contacting zone 4.

Contacting zone 4 may be equipped with heat exchange means, heatingmeans, and the like and is usually maintained under contactingconditions including a temperature of from about F. to 500 F., andpreferably a temperature of from about 300 F. to 400 F., and a pressurein the range of from about atmospheric to about 25 atmospheres,preferably 10 to 20 atmospheres, and a C6- Ca containing naphtha streamto petroleum crude oil feedstock ratio of from about 0.5 to 5.0, andpreferably from about .0 to 2.0. A heavy fraction stream is thusseparated from a light fraction stream in this contacting zone.

The heavy fraction stream is then passed via line 5 from contacting zone4 into fractionation zone 12, hereinafter described, which is maintainedunder distillation lconditions, and the light fraction stream is passedin admixture with a hydrogen containing gas stream via line 10,hereinafter described, to catalytic reaction zone 7 via line 6. Thecatalytic reaction zone is maintained under hydrocarbon conversionconditions wherein the light fraction stream is at least partiallyconverted into more valuable products.

In a preferred embodiment, the process of this invention is particularlyapplicable to the hydrorening of a petroleum crude oil feedstock asdelined hereinabove. Reaction zone 7 is of the conventional type `withthe conversion catalyst disposed therein in the reaction zone. Thereaction zone may be equipped with heat transfer means, baflles, trays,heating means, etc. The reaction zone is preferably of the adiabatictype and thus feed to the reaction zone will preferably be provided withthe requisite amount of heat prior to passage thereof to said reactionzone. The actual operation of the reaction zone may be upflow, downllow,or radial ow. A preferred hydrorelining catalyst which may be utilizedin the process of the present invention can be characterized ascomprising a metallic component possessing hydrogenation activity, whichcomponent is composited with a refractory inorganic oxide carriermaterial which may be of either synthetic or natural origin. The precisecomposition andmethod of manufacturing the catalytic composition is notconsidered to be an essential element of the present process.

However, a particularly suitable catalyst for use in my invention wouldcomprise a refractory inorganic oxide carrier material such asalumina,\silica, zirconia, magnesia, titania, boria, strontia, hafnia,etc. and mixtures thereof including silica-alumina, silica-zirconia,silicamagnesia, silica-titania, alumina-zirconia, silica-alumnaboronphosphate, alumina, magnesia, alumina-titania, magnesia-zirconia,titania-zirconia, magnesia-titania, silicaalumina-zirconia,silica-alumina-magnesia, silica-aluminatitania, silica-magnesia-zirconi,silica-alumina-boria. It is preferred to utilize a carrier materialcontaining at least a portion of silica, and it is particularlypreferred to utilize a composite of alumina and silica. Suitablemetallic components for hydrogenation activity are those selected fromthe group consisting of the metals of Groups IV-B and VIII of thePeriodic Table. Thus, the catalytic composition may comprise one or moremetallic components selected from the group consisting of molybdenum,tungsten, chromium, iron, cobalt, nickel, platinum, palladium, iridium,osmium, rhodium, ruthenium, and mixtures thereof. The concentration ofthe catalytically active metallic component or components is primarilydependent upon the particular metal utilized as well as thecharacteristics of the charge stock. The Group VI-B metal, such aschromium, molybdenum or tungsten is usually preferred in an amount offrom about 0.5% to about 10.0% by weight of the catalyst. The Group VIIImetals, which may be divided into two subgroups, namely the ironsubgroup and the noble metal subgroup, are Preferred in an amount ofabout `0.1% to about by weight of the total catalyst. When an ironsubgroup metal such as iron, cobalt or nickel, etc. is employed, it ispreferred in an `amount of from` about 0.2% to about 10.0% by weight.When a noble metal subgroup metal such as platinum, palladium oriridium, etc., is employed, it is preferred to utilize an amount withinthe range of from about 0.1% to about 5.0% by weight of the totalcatalyst.

When utilizing a hydroreiining catalyst such as described above,reaction zone 7 is maintained under hydroreining conversion conditionsincluding a temperature of from about 600 F. to about 1,000 F. asmeasured at the inlet to the iixed bed of the catalyst disposed Withinreaction zone 7. The reaction zone efuent passing via line 8 toseparation zone 9 will be at a higher temperature than that of thereactor inlet due to the exothermic nature of the reactions beingeffected. Hydrogen, via lines `6 and 10, as hereinafter described, aswell as via lines 1, 2, and 3, is passed to the reaction zone in anamount usually less than about 10,000 s.c.f./ bbl., and at the selectedoperating pressure which is usually maintained in the range of fromabout 1,000 to 4,000 p.s.i.g. The liquid hourly space velocity (beingdefined as the volume of liquid hydrocarbon charge per hour per volumeof catalyst disposed Within the reaction zone) is maintained in therange of from about 0.25 `to about 4.0.

As set forth hereinabove, the light fraction stream from contacting zone4 is at least partially converted into more valuable products inreaction zone 7. The efluent passing from reaction zone 7 via line 8, ispassed to separation zone 9. This eluent stream contains normallygaseous components, normally gaseous hydrocarbons, and normally liquidhydrocarbons which pass directly to separation zone 9 which ismaintained under separation conditions hereinafter deined.

Separation zone 9 may be a series of high pressure, low temperatureseparation vessels from which a hydrogenrich gas stream via line 10 isWithdrawn, and recycled via lines 10 and 6 to reaction zone 7. Ahydrocarbon-containing stream is then passed via line 11 from separationzone 9 to fractionation zone 12. It is also contemplated within thescope of this invention that anygnumbver of hot ash and/or cold flashsystems utilized in conjunction with a series of hot and/or coldseparators maintained in series llow or parallel ow or a combination ofboth flows, at different pressure is included within the generally broadscope of my separation zone 9.

IFractionation zone 12 may be of a conventional type and is utilized forobtaining an overhead fraction containing normally gaseous hydrocarbons,a lirst intermediate fraction comprising a Cs-Cs containing naphthafraction, a. second intermediate fraction containing desired valuablehydrocarbon product, and a bottoms fraction fraction comprising a majorportion of the heavy fraction as removed from contacting zone 4. Thefractionation zone 12 may be a series of fractional distillationcolumns. In the present preferred embodiment of this invention,fractionation zone 12 is represented as being a single distillationcolumn and operated at conditions of temperature and pressure so thatthe desired fractions can be recovered therefrom. In the drawing, anoverhead fraction containing normally gaseous hydrocarbon is removedfrom fractionation zone 12 via line 14. A first intermediate fractioncomprising a Cs-Ca containing naphtha fraction is removed frornfractionation zone 12 via line 13 and recycled to line 2 for passage tocontacting zone 4 via lines 2 and 3. A second intermediate fractioncontaining desired valuable hydrocarbon product is removed fromfractionation zone 12 and sent to storage (not shown) via line 15. Thebottoms fraction comprising a major portion of the heavy fraction streamfrom the contacting zone is removed from fractionation zone 12 via line16. This bottoms fraction may be discarded, treated for metals recoveryor, if desired, recycled through means not shown back to line 3 forfurther contacting in contacting zone 4.

Thus, by having the heavy fraction stream from contacting zone 4completely bypass the hydrorening reaction zone, the asphaltenes,organo-metallic complexes, carbon residue precursors and the like do notbecome involved in the hydrorelining reaction and longer catalyst lifeand higher, more selective yields of product can be achieved whenprocessing the light fraction stream obtained by contacting thepetroleum oil feedstock with the C-Cs containing naphtha stream in thecontacting zone.

The invention claimed:

1. A method for the conversion of a petroleum crude oil feedstock intomore valuable products which comprises:

(a) contacting said feedstock with a Cs-Cs naphtha and separating theresulting mixture into a heavy fraction and a light fraction;

(b) subjecting said light fractionto catalytic hydrore- -fning in areaction zone;

(c) passing the normally liquid hydrocarbon portion of the efliuent fromsaid reaction zone to a fractional distillation zone;

(d) bypassing said heavy fraction around said reaction zone andintroducing the heavy fraction into said distillation zone; and

(e) withdrawing from said distillation zone a first fraction comprisingCG-Cs naphtha, a second intermediate fraction comprising desiredvaluable hydrocarbon product, and a bottoms fraction comprising a majorportion of said heavy fraction as speciiied in step (d).

2. The method according toclaim 1 wherein said crude `oil feedstock isadmixed with hydrogen.

3. The method according to claim 1 wherein said contacting is eiected ata temperature of from about F. to 500 F. and a pressure in the range offrom about atmospheric to about 25 atmospheres and a C-Cs containingnaphtha stream to crude oil feedstock ratio of from about 0.5 to 5.0.

4. The method according to claim 1. wherein at least a portion of saidiirst intermediate fraction is recycled to step (a) as said Cs-Csnaphtha.

5. A method for the conversion of a petroleum crude oil feedstock intomore valuable products which comprises the steps of:

(a) contacting said feedstock with a C-Ca containing naphtha stream in acontacting zone maintained under contacting conditions wherein a heavyfraction stream is separated from a light fraction stream;

(b) passing said heavy fraction stream to a lower sec tion of afractionation zone maintained under distillation conditions and passingsaid light fraction stream in admixture with a hydrogen-containing gasstream to a hydrorening reaction zone containing a hydrorefiningcatalyst maintained under hydrorening conversion conditions rwhereinsaid light fraction stream is at least partially converted into morevaluable products;

(c) passing an eiiiuent stream containing normally gaseous components,normally gaseous hydrocarbons and normally liquid hydrocarbons from saidreaction zone directly to a separation zone maintained under separationconditions wherein said hydrogencontaining gas stream is recycled tosaid reaction zone and a hydrocarbon-containing stream is passed to saidfractionation zone;

(d) withdrawing from said fractionation zone an overhead fractioncontaining normally gaseous hydrocarbons, a first intermediate fractioncomprising a Cg-Cs containing naphtha fraction, a second intermediatefraction containing desired valuable hydrocarbon product, a bottomsfraction comprising a major portion of said heavy fraction as specifiedin 'Step (b); and,

(e) passing at least a portion of said first intermediate fraction intoadmixture with said C6-C8 containing naphtha stream as specified in Step(a).

6. The method according to claim 5 wherein said crude oil feedstock isad-mixed with hydrogen.

7. The method according to claim 5 wherein said contacting zone ismaintained at a temperature of from about F. to 500 F. and a pressure inthe range of from about atmospheric to about 25 atmospheres and a CG-Cscontaining naphtha stream to crude oil feedstock ratio of from about 0.5to 5.0.

References Cited UNITED STATES PATENTS 2,913,395 11/ 1959 Hanson 20S-2513,362,901 1/ 1968 Szepe et al 208-309 3,414,506 12/1968 Campagne 208-309HERBERT LEVINE, Primary Examiner U .S. Cl. XJR.

